A common and well-known form of harvesting machine is a rotary combine. Rotary combines are available in various designs and models to perform the basic functions of harvesting, threshing, and cleaning of grain and other crop materials.
A typical combine includes a crop harvesting apparatus which reaps planted gain stalks as the harvester is driven across the field. The grain stalks or other crop materials harvested in the field are introduced to a feeder mechanism. A conventional feeder mechanism includes a housing with a material conveyor assembly arranged for movement therewithin. The housing of the feeder mechanism mounts the header assembly to a frame of the combine for vertical movement and has a width of about 35 inches to about 45 inches between opposite sides thereof. The conveyor assembly within the feeder mechanism rearwardly and linearly moves the crop materials along a bottom wall or floor of the housing in a layer or mat formation. At its rear end, the conveyor assembly of the feeder mechanism discharges the crop materials into an open ended rotor assembly in a conventional undershot manner.
In rotary combines the rotor assembly includes a generally tubular rotor casing mounted on the frame of the combine and a driven rotor disposed within the casing in co-axial relationship therewith. The rotor and casing have cooperating threshing instrumentalities arranged thereon for separating grain from material other than grain. In such a combine, which has been available for a number of years, the crop materials are threshed several times repeatedly, but gently, as they spiral around the rotor and allows grain to pass through openings in the rotor casing.
The ability to transfer crop materials from the feeder mechanism to the rotor assembly is a key factor in efficient and effective combine operations. Many rotors suited to rotary combines include an impeller blade assembly comprised of a series of impeller blades arranged at the forward end of the rotor. During a harvesting operation, these rotating impeller blades change the generally linear movement of the crop materials received from the feeder mechanism into whirling circulatory movement in a rearward and outward direction relative to the axis of rotation of the rotor. The outward circulatory movements allows spiral vanes on the interior surface of the rotor casing to thereafter engage and facilitate rearward crop material movements through the rotor assembly for threshing.
The linear distance separating the discharge end of the feeder mechanism from the foremost face of the whirling impeller blades represents a crop material transition area. Within this transition area, the movements of crop materials must convert or change from generally linear movements to generally circulatory movements. As will be appreciated by those skilled in the art, and depending upon the rotational direction of the rotor, those crop materials moving along and disposed generally to one side of the feeder mechanism housing will readily adapt to the change in direction of travel (linear v. circulatory) as compared to those crop materials moving along and disposed to an opposite side of the feeder mechanism housing.
The problems involved with changing the direction of the crop materials in the transition area extending between the feeder mechanism and rotor assembly are exacerbated when the rotary combine is used in long-stemmed leguminous or grassy crops, such as windowed perineal or annual rye grass, clover and bent grass. Such crop materials tend to have difficulty in transferring between a linear movement associated with the feeder mechanism and a circulatory movement associated with the rotary or circularly moving impeller blades.
Stones, rocks and other forms of hard objects are typically present in the fields over which the combine moves. As it will be appreciated, the introduction of stones, rocks and other hard objects into the rotor assembly of a combine can present serious problems and hinder operation of the combine. Of particular concern is the damage that such stones, rocks and other hard debris impart to the threshing cylinder and cooperating threshing instrumentalities of the rotor assembly.
Various devices have been heretofore used to inhibit the stones or rocks, passing into the rotor assembly of the combine. One such device includes a rock trap beater assembly which is conventionally mounted toward a discharge end of the feeder assembly. Those combines incorporating a rock trap beater assembly typically include a rock holding area disposed along the bottom wall of the feeder housing and into which the beater diverts rocks and stones prior to their introduction to the rotor assembly. The rock trap beater assembly includes a rotary member which extends transversely across the feeder housing and includes a plurality of transverse vanes or beaters which engage and trap the crop material against the floor of the feeder housing immediately prior to the introduction of the crop materials into the rotor assembly. Trapping the materials against the floor of the feeder housing immediately prior to the introduction of the crop materials into the rotor assembly, of course, tends to further complicate the transition for the crop materials moving between a linear movement and a circulatory movement.
Increasing the speeds of the conveyor assembly of the feeder mechanism to force the crop materials into the rotor assembly has not provided a solution to this common problem associated with rotary combines. Increasing the linear speed of the crop materials through the feeder mechanism has been found to further complicate combine operations by causing feedback problems as well as causing excessive power consumption thus detracting from the efficiency and effectiveness of the combine.
Thus, there is a need and a desire for a feeder-rotor assembly having a transition area which allows the crop material to change from a linear flow to a rotary or circular flow after release from the feeder mechanism and to seek the path of least resistance while under the influence of the rotor.